<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Dear Paola,<div class=""><br class=""></div><div class="">it seems that the answer I sent last week bounced somehow so I copy and paste it here:</div><div class=""></div><blockquote type="cite" class=""><div class="">Hi Paola,<br class="">I suspect that the grid line path generated by gcmfaces_lines_transp_lat.m is affected by the change in end points. If that is the case you should see differences mskCedge etc.<br class="">Hope this helps,<br class="">Gael</div></blockquote><div class=""><br class=""><div>ps: thanks Ian for pointing out that my email had bounced</div><div><br class=""><blockquote type="cite" class=""><div class="">On Feb 23, 2018, at 10:08 PM, Fenty, Ian G (329C) <<a href="mailto:Ian.Fenty@jpl.nasa.gov" class="">Ian.Fenty@jpl.nasa.gov</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="WordSection1" style="page: WordSection1; font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;"><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">Dear Paola,<span class="Apple-converted-space"> </span><o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><o:p class=""> </o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">Land points in ECCO v4 are defined on a curvilinear grid whose parameters are laid out in the different files of the nctiles_grid/ directory. The grid parameters for your domain are found in nctiles_grid/GRID.0012.nc. Each model grid cell has a land mask defined at their center XC (longitude), YC (latitude). Each cell has four corners, defined at the points XG, YG. <o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><o:p class=""> </o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">I plotted the land mask (hFacC) below. Land points are empty white boxes and water points have red dots. The grid cell boundaries are plotting using XG and YG. <o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><o:p class=""> </o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">There is a water grid cell that spans approximately 72W to 71W at 30S. The grid cell to the east of that cell spans approximately 71W to 70W and is land. At first glance it would appear that the transport should not change when you move the eastern endpoint to 70W from 71W. However, you are picking points very close to the grid cell edge. The curvilinear grid is not defined with exactly integer meridians so this might be the source of the problem. <o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><o:p class=""> </o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">Can you please try to redo the calculation using 69W as the endpoint to see if you get the same value as when 70W is the endpoint? If so, then it would suggest that the first calculation was not counting the grid cell between 72W and 71W in the transport calculation. <span class="Apple-converted-space"> </span><o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><o:p class=""> </o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">Perhaps Gael might have more to say about this as he wrote the calc_transports routine.<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><o:p class=""> </o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">Do let us know what you find. <span class="Apple-converted-space"> </span><o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><o:p class=""> </o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class="">Ian<o:p class=""></o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><o:p class=""> </o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><o:p class=""> </o:p></div><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span id="cid:image001.png@01D3ACD9.AFB7B7D0"><image001.png></span><o:p class=""></o:p></div><div class=""><div class=""><div style="margin: 0in 0in 0.0001pt 0.5in; font-size: 11pt; font-family: Calibri, sans-serif;" class="">On 2/22/18, 4:16 PM, "<a href="mailto:ecco-support-bounces@mit.edu" style="color: purple; text-decoration: underline;" class="">ecco-support-bounces@mit.edu</a><span class="Apple-converted-space"> </span>on behalf of Paola Cessi" <<a href="mailto:ecco-support-bounces@mit.edu" style="color: purple; text-decoration: underline;" class="">ecco-support-bounces@mit.edu</a><span class="Apple-converted-space"> </span>on behalf of<span class="Apple-converted-space"> </span><a href="mailto:pcessi@ucsd.edu" style="color: purple; text-decoration: underline;" class="">pcessi@ucsd.edu</a>> wrote:<o:p class=""></o:p></div></div></div><div class=""><div style="margin: 0in 0in 0.0001pt 0.5in; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><o:p class=""> </o:p></div></div><div style="margin: 0in 0in 0.0001pt 0.5in; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><a name="_MailOriginalBody" class="">I am confused as why the values of transports across a section, as given by calc_transports, change when the endpoints of the section, as given by calc_transports, are changed by one or two degree on land points. For example, if I change gcmfaces_lines_transp([152 -71],[-30 -30],{'30S Pacific'}); to gcmfaces_lines_transp([152 -70],[-30 -30],{'30S Pacific'}); the transports are different even though<o:p class=""></o:p></a></div><div class=""><div style="margin: 0in 0in 0.0001pt 0.5in; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span class="">both 70W 30S and 71W 30S are on land (at least on google maps). Why does this happen? Is there documentation on the actual land point in ECCO, given in lat-lon? <o:p class=""></o:p></span></div></div><div class=""><div style="margin: 0in 0in 0.0001pt 0.5in; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span class=""><o:p class=""> </o:p></span></div></div><div class=""><div style="margin: 0in 0in 0.0001pt 0.5in; font-size: 11pt; font-family: Calibri, sans-serif;" class=""><span class="">Thanks,<o:p class=""></o:p></span></div><div class=""><div class=""><div class=""><p class="MsoNormal" style="margin: 0in 0in 15pt 0.5in; font-size: 11pt; font-family: Calibri, sans-serif;"><span class=""><span style="font-size: 15pt; font-family: Helvetica;" class=""><br class="">Paola</span></span></p></div></div></div></div></div></div></blockquote></div><br class=""></div></body></html>